The background pulses brightness and saturation on a 9-second sine cycle. This is the most primitive synthetic signal of life. Everything else sits on top of this heartbeat. If you removed all other effects, the scene would still feel inhabited.
Lift away even the heartbeat and something stays: grass leaning in the wind, clouds drawn slowly across the valley. This motion was never written into the page — it was already there, caught in the instant the image was made. The first aliveness isn't a signal we add. It's the world, continuing without us.